You may have caught a glimpse of the Virginia Opossum's moon-white face on your back fence. Opossums, North America's only marsupial, are also part of the Earth's oldest surviving mammal family -- fossil remains have been found from 70 million years ago.

Nocturnal and transient, opossums will spend two or three days in the same location, then move on. They are omnivorous, eating berries, grasses and leaves, as well as insects (roaches and beetles), snails and slugs, rats, and carrion such as road-kill. Like vultures, opossums are Nature's sanitation engineers, and help to maintain a clean and healthy environment in our neighborhood.

Because opossums can't jump, they can only get in a trash can if it has been knocked over by another animal, or if the can is against a fence and the possum drops into it. If you find one in your trash can, tip the can over and it will leave.

Opossums are slow-moving and have very sensitive ears and noses. The size of a cat, their fur is most commonly gray. Baby opossums are usually born between February and June. Females have litters of five to eight, up to twice a year. Twenty newborns can fit into a teaspoon! At three months of age, baby opossums can be seen riding on mothers back, or in her pouch. They are ready to leave the pouch at four months when they are nine inches long and weigh one pound.

It's not an easy life -- few live beyond the age of one year due to their many predators: humans (and cars), dogs, cats, and owls.

"Playing possum" is not a myth, it's the most effective way the they defend themselves. When unable to escape, extreme fear places the opossum into an involuntary coma. They become stiff and their mouths will gape open; this condition can last forty minutes to four hours. Most predators will abandon their attack once the opossum is thought to be dead.

Another possum defense is to hiss, growl, drool, and show their fifty sharp teeth (more teeth than any other mammal). This is another bluff, as opossums are really gentle and placid and prefer to avoid confrontations.

Opossums do not dig into the soil, nor do they destroy property. Their front paws have soft, delicate skin and small nails. The rear feet have opposable thumbs, allowing the opossum to grasp and hold branches in a manner similar to a human hand. They also use their feet to groom themselves. They can not hang by their furless, prehensile tail; it simply works as a fifth limb to help balance or lower themselves to the ground.

For more information on opossums, visit www.opossumsocietyus.org. And have fun exploring your own backyard!

© Carol Wells, 2008